The eddy covariance technique, which is used in the determination of net ecosystem CO2 exchange (NEE), is subject to significant errors when advection that carries CO2 in the mean flow is ignored. We measured horizontal and vertical advective CO2 fluxes at the Niwot Ridge AmeriFlux site (Colorado, USA) using a measurement approach …
Journal: Ecological Applications, Volume 18 (6): 1379-1390 (2008), ISBN . DOI: 10.1890/06-0908.1 Sites: US-NR1
Stable isotopes provide insight into ecosystem carbon cycling, plant physiological processes, atmospheric boundary-layer dynamics, and are useful for the integration of processes over multiple scales. Of particular interest is the carbon isotope content (δ13C) of nocturnal ecosystem-respired CO2 (δR). Recent advances in technology …
Journal: Agricultural And Forest Meteorology, Volume 148 (4): 592-605 (2008), ISBN . DOI: 10.1016/j.agrformet.2007.11.003 Sites: US-NR1
We investigate the utility of an improved isotopic method to partition the net ecosystem exchange of CO2 (F) into net photosynthesis (FA) and nonfoliar respiration (FR). Measurements of F and the carbon isotopic content in air at a high‐elevation coniferous forest (the Niwot Ridge AmeriFlux site) were used to partition F into FA …
Journal: Global Change Biology, Volume 14 (8): 1785-1800 (2008), ISBN . DOI: 10.1111/j.1365-2486.2008.01609.x Sites: US-NR1
Journal: Global Change Biology, Volume : (2008), ISBN . DOI: 10.1111/j.1365-2486.2008.01675.x Sites: US-SP1, US-SP3
Journal: Agricultural And Forest Meteorology, Volume 148 (2): 158-170 (2008), ISBN . DOI: 10.1016/j.agrformet.2007.08.004 Sites: US-UMB
Journal: Bioscience, Volume 58 (7): 609-622 (2008), ISBN . DOI: 10.1641/B580708 Sites: US-UMB
Riparian evapotranspiration (ET) is a major component of the surface and subsurface water balance for many semiarid watersheds. Measurement or model-based estimates of ET are often made on a local scale, but spatially distributed estimates are needed to determine ET over catchments. In this paper, we document the ET that was quantified …
Journal: Journal Of Arid Environments, Volume 72 (7): 1232-1246 (2008), ISBN . DOI: 10.1016/j.jaridenv.2008.01.001 Sites: US-CMW, US-LS1
Scrub oak and pine flatwoods are two contrasting ecosystems common to the humid
subtropical climate of Florida. Scrub oak forests are short in stature (<2 m) and occur on
well-drained sandy soils, and pine flatwoods are much taller and occur in areas with
poorly drained soils. Eddy covariance measurements were made from January …
Journal: Journal Of Geophysical Research: Biogeosciences, Volume 113 (G2): n/a-n/a (2008), ISBN . DOI: 10.1029/2007JG000469 Sites: US-KL2, US-KS1
The pathway to summertime convective precipitation remains a vexing research problem because of the nonlinear feedback between soil moisture content and the atmosphere. Understanding this feedback is important to the southeastern U. S. region, given the high productivity of the timberland area and the role of summertime convective …
Journal: Water Resources Research, Volume 43 (3): n/a-n/a (2007), ISBN . DOI: 10.1029/2006WR004954 Sites: US-Dk2
Filtering methods based on morphological operations have been developed in some previous studies. The biggest challenge for these methods is how to keep the terrain features unchanged while using large window sizes for the morphological opening. Zhang et al. (2003) tried to achieve this goal, but their method required the assumption …
Journal: Photogrammetric Engineering & Remote Sensing, Volume 73 (2): 175-185 (2007), ISBN . DOI: 10.14358/pers.73.2.175 Sites: US-Ton